Ideas to simultaneously reduce greenhouse gas emissions, save foreign exchange and create many jobs
Wouldn’t it be nice if some-body developed a project which simultaneously reduced greenhouse gas emissions, saved foreign exchange and created many jobs?
This is how it could be done: produce biofuels from crops grown on poor soil, using drip irrigation and manual labour. (Over 50% of the grain grown is fed to animals farmed for their meat… go vegetarian and use that land for growing biofuels. Ed.)
The following is a simplified description of how this could be done in South Africa based upon work by Dr RE Robinson (a distinguished chemical engineer and businessman, now retired).
The use of biofuels is neither new nor technologically difficult. It is already done in some countries on a significant scale; an example is Brazil.
Previous proposals on the replacement of petroleum based fuels by biofuels have floundered for a number of reasons.
These included fossil fuel being cheaper, the unavailability of sufficient suitable arable land, inadequate water supply, etc. With the recent increase in petroleum prices the situation has now changed.
Dr Robinson makes it clear that he is promoting the production of biofuels from agriculture in South Africa primarily to address the crisis of unemployment in the rural area and the mass migration of impoverished people into squatter camps surrounding all urban areas in search of a means of survival. He suggests a target of a million new jobs, predominantly in rural areas.
The probability of a million jobs being created in the forseeable future by expansion in manufacturing, tourism, mining or the services and infrastructure sectors of the economy seems low. At first sight, the same might be said of the agricultural sector.
There are well-known limitations to the expansion of commercial farming due to factor such as shortages of good quality arable land and water and especially because of market saturation or tarriff barriers.
However, this may not be the case if the focus is on the production of fuel. There are well established commercial process for producing ethanol from maize or sugar cane or several other crops such as sorghum and cassava. Biodiesel fuel is based on vegetable oils from soya bean, sunflower or the Jatropha plant.
How then can one possibly contemplate the creation of a million jobs for unskilled rural farmers making a sustainable living from biofuels? The answer lies in an agricultural technology which is widely used in Israel and other water hungry countries. This is known as sub-surface irrigation (SSI) referred to colloquially as drip irrigation, which ranges from highly sophisticated computerized models to a simple version of plastic tubes with drip holes at the correct intervals.
The basic feature of all the models is to feed each plant individually with the correct amount of water containing the correct quantity of nutrients at the stem of each plant. This allows the root system of the plant to take up the water easily and continuously without having to extend widely and deeply as takes place in good soil supplied with plenty of water.
Many studies have been done on SSI. The most authoritative results are probably those from the Pratt Research organisation in Australia which indicate that, in terms of water transpiration, SSI is about 85% efficient, as compared with the best of overhead irrigation systems of 15%.
Note that the nutrients, being in the water, are delivered where they are needed, only where they are needed, and at the time in the growth of the plant that they are required. Hence the quantity of fertilizer required is very much less than in conventional irrigated systems. A much reduced cost applies. The reason why this system has not taken over agriculture in most countries is that it is highly labour intensive. But that is precisely Dr Robinson’s objective.
The use of SSI makes is possible to convert from a batch (one crop per season) farming system to one requiring continuous, manual daily harvesting and planting. Under such a system, one unskilled farmer working on two small units occupying in total of 0.15 ha can produce about 10 tons of maize and 10 tons of soya beans per annum which can be supplied to a fuel plant on a continuous daily basis at a price of ca R600. per ton. ie. an income of R12000 pa for the farmer. This can be augmented to the order of R20000. pa if his by-products are utilised optimally.
These by-products are mainly the biomass (stalks, leaves etc) left after the crop itself is separated. For 1 million farmers, each using 0.15 ha, a total of 150 000 hectares would be required. Due to the use of sub-surface irrigation (and fertilization) good quality arable land is not necessary. The water requirement for the 1 million farmers would be no more that 3000 megalitres per day; furthermore processed sewage affluent would be ideal, as would treated mine water.
The plots would be in groups in various areas of the country. The groups would however have to be sufficiently large to justify the construction of a treatment plant in the vicinity. The products from the farmers would be purchased by the treatment plant which would produce ethanol, (a petrol substitute), from the maize and biodiesel from soya. Dr. Robinson calculates that the one million farmers could produce some 4000 million litres of ethanol and a similar quantity of biodiesel per annum.
Apart from the enormous benefit of the jobs created, an advantage to the economy of South Africa would be the avoidance of the need to import fuels costing some R20 billion every year. The advantage to the world at large would be a decrease of some 30 million tons of carbon dioxide discharged into the atmosphere per annum.
Dr. Robinson suggests that a high estimate of the capital cost is R50 billion, which, at R50 000 per job created is low by most standards.
Coming down to earth a bit from the heady thought of a million new jobs, it is important to note that drip irrigation is already in use profitably on a small scale in a number of locations in South Africa on poor soils for the production of various crops.
So we have a base from which to work. what is now needed is to grab the attention of “the powers that be” to provide incentives for the development of the system into biofuel crop production and the use thereof in our vehicles.